Deformation of excessively wet subgrade is often problematic during pavements construction as well as under regular vehicular traffic loads. In order to create a sturdy and stable platform for heavy traffic pavement, a “green materials” based entirely on industry byproduct of combination fly ash (FA) with carbide lime (CL) and flue gas desulfurization gypsum (FGDG) was proposed in this study. In order to investigate the effectiveness and improvement of engineering properties, solidification test and compaction test were carried out in laboratory, and Dynamic Cone Penetrometer (DCP) was conducted at the construction site. Investigation results showed significant improvement in drying rate, workability, and mechanical behavior. The addition of FA/CL/FDG stabilizer increases the solids content by “bulking” and reduces the free moisture through hydration reactions. The addition of FA/CL/FGDG leads to an increase of approximately 18% in the maximum allowable moisture content, which would largely facilitate the compaction of the excessively wet soils. Post construction evaluation using DCP indicates the stabilized soil can be utilized under high volume traffic condition.